The present invention relates to a device for use in making a ring coil by an automatic winding machine.
The number of turns of the ring coil of an electrical device such as transformer or inductance may be several thousands. Before the invention of automatic coil winding machines, it took about one working day to finish the winding of a ring coil. The use of an automatic coil winding machine greatly improves the production speed of ring coils. A ring coil is normally made by winding an enamel wire round an insulated annular iron core. The insulation between the annular iron core and the winding of enamel wire is now commonly consisted of two symmetrical annular insulation shields attached together to hold the annular iron core in between. Although the use of an automatic coil winding machine greatly improves the winding speed of ring coils, there are still problems to be settled. Because the leading end of the enamel wire is not fixed, it will be forced to displace as the enamel wire passes over after each run of winding (360.times.around the central axis). If the leading end of the enamel wire is displaced, the quality and service life of the ring coil will be affected. In order to eliminate this problem, the automatic coil winding machine must be temporarily stopped to let the enamel wire be moved over the leading end with the hand each time the enamel wire is wound round the ring coil insulation shield through 360.times.around the central axis of the annular iron core and reached the leading end again.